Although named after the emerald, the classic emerald cut can showcase the color of any gem. Easy to facet, the Gram Easy Emerald by Jeff Graham will maximize yield. This design and its cutting sequence will also accommodate gemstones with arbitrary length to width ratios.
By Jeff R. Graham 2 minute read
Gram Easy Emerald gem design by Jeff Graham © 1999.

Gram Easy Emerald gem design by Jeff Graham © 1999.

You can find cutting instructions for the Gram Easy Emerald here.

Gram Easy Emerald - tourmaline

A 13.6-ct, 8.8 x 25.3 mm Gram Easy Emerald, cut from yellow tourmaline by Jeff Graham. This gem has a length to width ratio of 2.9:1. Since this particular tourmaline is black on the c-axis, relatively steep pavilion facets on the end steps help minimize the darkening effect of the black axis on the ends of the stone.

Cutting Remarks

First, cut the stone to a rectangular outline, then follow with two courses of pavilion steps. The P5 steps on the second course are cut in until the width across the face of the P3 facets on the first course is reduced to approximately 0.227W, where W is the width of the stone. Thus, if you have a 10 mm wide stone, cut in P5 until the width of P3 reduces to 2.27 mm. (0.227 x 10 mm = 2.27 mm). At both ends, of course.

You can use an inexpensive pair of calipers to make that measurement, but it need not be exact. You could even determine it by “calibrated eyeball.” However, the closer the width of P3 comes to 0.227W, the closer your corners will come to matching the relative proportions shown in the three views.

Gram Easy Emerald - proportions

Corner Facet Notes

Establish the width of the corners (12, 36, 60, and 84) by cutting the P6(G) facets through the girdle to meetpoints at the bottom of the first step. The lower portion of P6(G) is subsequently overcut at 72° by P7, creating the pavilion girdle line on the corners. The wider you leave P3, the wider and deeper the corner facets. I cut the yellow tourmaline in the photo with the width of P3 approximately equal to 0.300W. Note how its table is cut through the C4, C5, and C6 meetpoints, with the effect of adding embellishing bevels at the table corners and making it larger.

Pavilion Notes

The pavilion ends (24, 72) are relatively steep to help keep from darkening or mixing muddy colors on the c-axis and to improve yield. For darker materials, you could tangent ratio the crown to reduce its depth. In most cases, however, I would rather have the dispersion of the deeper crown.

The P3 outer pavilion facets light up when you rock the stone, and the P5 and P10 inside blink. This gives the classic “emerald” look that I prefer.

Enjoy cutting your Gram Easy Emerald.

Gram Easy Emerald - array

Random – Cosine – ISO

Detailed faceting instructions by Jeff Graham available at The Rock Peddler